DESCRIPTION: The purpose of this study is to determine whether children with SLI and normally-developing children are similar in their sensitivity to the acoustic-phonetic properties of function words, in their reliance on function words in story comprehension, and in the neurophysiological correlates of function word perception. Answers to these questions are designed to tease apart and/or clarify different versions of perceptual processing theories of SLI. Forty preschool-aged children with SLI and 40 age-matched controls will comple two studies that involve listening to stories presented auditorally. ERPs wil be recorded as the children process function words and nonsense syllables that are embedded in stories. The only differences between the stories are the acoustic properties of the normal function words and the nonsense syllables. After hearing sections of each story, participants will point to a picture tha represents what a character in the story saw. After listening to the stories, participants will complete a basic auditory discrimination task.